| 1 | /* |
| 2 | * query.c |
| 3 | * - overall query management (allocation, completion) |
| 4 | * - per-query memory management |
| 5 | * - query submission and cancellation (user-visible and internal) |
| 6 | */ |
| 7 | /* |
| 8 | * This file is part of adns, which is Copyright (C) 1997, 1998 Ian Jackson |
| 9 | * |
| 10 | * This program is free software; you can redistribute it and/or modify |
| 11 | * it under the terms of the GNU General Public License as published by |
| 12 | * the Free Software Foundation; either version 2, or (at your option) |
| 13 | * any later version. |
| 14 | * |
| 15 | * This program is distributed in the hope that it will be useful, |
| 16 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 18 | * GNU General Public License for more details. |
| 19 | * |
| 20 | * You should have received a copy of the GNU General Public License |
| 21 | * along with this program; if not, write to the Free Software Foundation, |
| 22 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 23 | */ |
| 24 | |
| 25 | #include "internal.h" |
| 26 | |
| 27 | #include <stdlib.h> |
| 28 | #include <unistd.h> |
| 29 | #include <errno.h> |
| 30 | #include <string.h> |
| 31 | |
| 32 | #include <sys/time.h> |
| 33 | |
| 34 | #include "internal.h" |
| 35 | |
| 36 | int adns__internal_submit(adns_state ads, adns_query *query_r, |
| 37 | const typeinfo *typei, vbuf *qumsg_vb, int id, |
| 38 | adns_queryflags flags, struct timeval now, |
| 39 | adns_status failstat, const qcontext *ctx) { |
| 40 | adns_query qu; |
| 41 | |
| 42 | qu= malloc(sizeof(*qu)); if (!qu) goto x_nomemory; |
| 43 | qu->answer= malloc(sizeof(*qu->answer)); if (!qu->answer) goto x_freequ_nomemory; |
| 44 | |
| 45 | qu->ads= ads; |
| 46 | qu->state= query_udp; |
| 47 | qu->back= qu->next= qu->parent= 0; |
| 48 | LIST_INIT(qu->children); |
| 49 | qu->siblings.next= qu->siblings.back= 0; |
| 50 | LIST_INIT(qu->allocations); |
| 51 | qu->interim_allocd= 0; |
| 52 | qu->final_allocspace= 0; |
| 53 | |
| 54 | qu->typei= typei; |
| 55 | adns__vbuf_init(&qu->vb); |
| 56 | |
| 57 | qu->cname_dgram= 0; |
| 58 | qu->cname_dglen= qu->cname_begin= 0; |
| 59 | |
| 60 | qu->id= id; |
| 61 | qu->flags= flags; |
| 62 | qu->udpretries= 0; |
| 63 | qu->udpnextserver= 0; |
| 64 | qu->udpsent= qu->tcpfailed= 0; |
| 65 | timerclear(&qu->timeout); |
| 66 | memcpy(&qu->ctx,ctx,sizeof(qu->ctx)); |
| 67 | |
| 68 | qu->answer->status= adns_s_ok; |
| 69 | qu->answer->cname= 0; |
| 70 | qu->answer->type= typei->type; |
| 71 | qu->answer->nrrs= 0; |
| 72 | qu->answer->rrs= 0; |
| 73 | qu->answer->rrsz= typei->rrsz; |
| 74 | |
| 75 | *query_r= qu; |
| 76 | |
| 77 | qu->query_dglen= qumsg_vb->used; |
| 78 | if (qumsg_vb->used) { |
| 79 | qu->query_dgram= malloc(qumsg_vb->used); |
| 80 | if (!qu->query_dgram) { |
| 81 | adns__query_fail(qu,adns_s_nomemory); |
| 82 | return adns_s_ok; |
| 83 | } |
| 84 | memcpy(qu->query_dgram,qumsg_vb->buf,qumsg_vb->used); |
| 85 | } else { |
| 86 | qu->query_dgram= 0; |
| 87 | } |
| 88 | qu->vb= *qumsg_vb; |
| 89 | adns__vbuf_init(qumsg_vb); |
| 90 | |
| 91 | if (failstat) { |
| 92 | adns__query_fail(qu,failstat); |
| 93 | return adns_s_ok; |
| 94 | } |
| 95 | adns__query_udp(qu,now); |
| 96 | adns__autosys(ads,now); |
| 97 | |
| 98 | return adns_s_ok; |
| 99 | |
| 100 | x_freequ_nomemory: |
| 101 | free(qu); |
| 102 | x_nomemory: |
| 103 | adns__vbuf_free(qumsg_vb); |
| 104 | return adns_s_nomemory; |
| 105 | } |
| 106 | |
| 107 | int adns_submit(adns_state ads, |
| 108 | const char *owner, |
| 109 | adns_rrtype type, |
| 110 | adns_queryflags flags, |
| 111 | void *context, |
| 112 | adns_query *query_r) { |
| 113 | qcontext ctx; |
| 114 | int id, r, ol; |
| 115 | vbuf vb; |
| 116 | adns_status stat; |
| 117 | const typeinfo *typei; |
| 118 | struct timeval now; |
| 119 | |
| 120 | typei= adns__findtype(type); |
| 121 | if (!typei) return adns_s_unknownrrtype; |
| 122 | |
| 123 | ctx.ext= context; |
| 124 | ctx.callback= 0; |
| 125 | memset(&ctx.info,0,sizeof(ctx.info)); |
| 126 | |
| 127 | r= gettimeofday(&now,0); if (r) return errno; |
| 128 | id= 0; |
| 129 | |
| 130 | adns__vbuf_init(&vb); |
| 131 | |
| 132 | ol= strlen(owner); |
| 133 | if (ol<=1 || ol>DNS_MAXDOMAIN+1) { stat= adns_s_querydomaintoolong; goto xit; } |
| 134 | |
| 135 | if (owner[ol-1]=='.' && owner[ol-2]!='\\') { flags &= ~adns_qf_search; ol--; } |
| 136 | |
| 137 | stat= adns__mkquery(ads,&vb,&id, owner,ol, typei,flags); |
| 138 | |
| 139 | xit: |
| 140 | return adns__internal_submit(ads,query_r, typei,&vb,id, flags,now, stat,&ctx); |
| 141 | } |
| 142 | |
| 143 | int adns_synchronous(adns_state ads, |
| 144 | const char *owner, |
| 145 | adns_rrtype type, |
| 146 | adns_queryflags flags, |
| 147 | adns_answer **answer_r) { |
| 148 | adns_query qu; |
| 149 | int r; |
| 150 | |
| 151 | r= adns_submit(ads,owner,type,flags,0,&qu); |
| 152 | if (r) return r; |
| 153 | |
| 154 | r= adns_wait(ads,&qu,answer_r,0); |
| 155 | if (r) adns_cancel(qu); |
| 156 | |
| 157 | return r; |
| 158 | } |
| 159 | |
| 160 | static void *alloc_common(adns_query qu, size_t sz) { |
| 161 | allocnode *an; |
| 162 | |
| 163 | if (!sz) return qu; /* Any old pointer will do */ |
| 164 | assert(!qu->final_allocspace); |
| 165 | an= malloc(MEM_ROUND(MEM_ROUND(sizeof(*an)) + sz)); |
| 166 | if (!an) return 0; |
| 167 | LIST_LINK_TAIL(qu->allocations,an); |
| 168 | return (byte*)an + MEM_ROUND(sizeof(*an)); |
| 169 | } |
| 170 | |
| 171 | void *adns__alloc_interim(adns_query qu, size_t sz) { |
| 172 | sz= MEM_ROUND(sz); |
| 173 | qu->interim_allocd += sz; |
| 174 | return alloc_common(qu,sz); |
| 175 | } |
| 176 | |
| 177 | void *adns__alloc_mine(adns_query qu, size_t sz) { |
| 178 | return alloc_common(qu,MEM_ROUND(sz)); |
| 179 | } |
| 180 | |
| 181 | void adns__transfer_interim(adns_query from, adns_query to, void *block, size_t sz) { |
| 182 | allocnode *an; |
| 183 | |
| 184 | if (!block) return; |
| 185 | an= (void*)((byte*)block - MEM_ROUND(sizeof(*an))); |
| 186 | |
| 187 | assert(!to->final_allocspace); |
| 188 | assert(!from->final_allocspace); |
| 189 | |
| 190 | LIST_UNLINK(from->allocations,an); |
| 191 | LIST_LINK_TAIL(to->allocations,an); |
| 192 | |
| 193 | from->interim_allocd -= sz; |
| 194 | to->interim_allocd += sz; |
| 195 | } |
| 196 | |
| 197 | void *adns__alloc_final(adns_query qu, size_t sz) { |
| 198 | /* When we're in the _final stage, we _subtract_ from interim_alloc'd |
| 199 | * each allocation, and use final_allocspace to point to the next free |
| 200 | * bit. |
| 201 | */ |
| 202 | void *rp; |
| 203 | |
| 204 | sz= MEM_ROUND(sz); |
| 205 | rp= qu->final_allocspace; |
| 206 | assert(rp); |
| 207 | qu->interim_allocd -= sz; |
| 208 | assert(qu->interim_allocd>=0); |
| 209 | qu->final_allocspace= (byte*)rp + sz; |
| 210 | return rp; |
| 211 | } |
| 212 | |
| 213 | static void cancel_children(adns_query qu) { |
| 214 | adns_query cqu, ncqu; |
| 215 | |
| 216 | for (cqu= qu->children.head; cqu; cqu= ncqu) { |
| 217 | ncqu= cqu->siblings.next; |
| 218 | adns_cancel(cqu); |
| 219 | } |
| 220 | LIST_INIT(qu->children); |
| 221 | } |
| 222 | |
| 223 | void adns__reset_cnameonly(adns_query qu) { |
| 224 | assert(!qu->final_allocspace); |
| 225 | cancel_children(qu); |
| 226 | qu->answer->nrrs= 0; |
| 227 | qu->answer->rrs= 0; |
| 228 | qu->interim_allocd= qu->answer->cname ? MEM_ROUND(strlen(qu->answer->cname)+1) : 0; |
| 229 | } |
| 230 | |
| 231 | static void free_query_allocs(adns_query qu) { |
| 232 | allocnode *an, *ann; |
| 233 | |
| 234 | cancel_children(qu); |
| 235 | for (an= qu->allocations.head; an; an= ann) { ann= an->next; free(an); } |
| 236 | adns__vbuf_free(&qu->vb); |
| 237 | } |
| 238 | |
| 239 | void adns_cancel(adns_query qu) { |
| 240 | switch (qu->state) { |
| 241 | case query_udp: case query_tcpwait: case query_tcpsent: |
| 242 | LIST_UNLINK(qu->ads->timew,qu); |
| 243 | break; |
| 244 | case query_child: |
| 245 | LIST_UNLINK(qu->ads->childw,qu); |
| 246 | break; |
| 247 | case query_done: |
| 248 | LIST_UNLINK(qu->ads->output,qu); |
| 249 | break; |
| 250 | default: |
| 251 | abort(); |
| 252 | } |
| 253 | free_query_allocs(qu); |
| 254 | free(qu->answer); |
| 255 | free(qu); |
| 256 | } |
| 257 | |
| 258 | static void makefinal_query(adns_query qu) { |
| 259 | adns_answer *ans; |
| 260 | int rrn; |
| 261 | |
| 262 | ans= qu->answer; |
| 263 | |
| 264 | if (qu->interim_allocd) { |
| 265 | ans= realloc(qu->answer, MEM_ROUND(MEM_ROUND(sizeof(*ans)) + qu->interim_allocd)); |
| 266 | if (!ans) goto x_nomem; |
| 267 | qu->answer= ans; |
| 268 | } |
| 269 | |
| 270 | qu->final_allocspace= (byte*)ans + MEM_ROUND(sizeof(*ans)); |
| 271 | adns__makefinal_str(qu,&ans->cname); |
| 272 | |
| 273 | if (ans->nrrs) { |
| 274 | adns__makefinal_block(qu, &ans->rrs.untyped, ans->nrrs*ans->rrsz); |
| 275 | |
| 276 | for (rrn=0; rrn<ans->nrrs; rrn++) |
| 277 | qu->typei->makefinal(qu, ans->rrs.bytes + rrn*ans->rrsz); |
| 278 | } |
| 279 | |
| 280 | free_query_allocs(qu); |
| 281 | return; |
| 282 | |
| 283 | x_nomem: |
| 284 | qu->answer->status= adns_s_nomemory; |
| 285 | qu->answer->cname= 0; |
| 286 | adns__reset_cnameonly(qu); |
| 287 | free_query_allocs(qu); |
| 288 | } |
| 289 | |
| 290 | void adns__query_done(adns_query qu) { |
| 291 | adns_answer *ans; |
| 292 | adns_query parent; |
| 293 | |
| 294 | qu->id= -1; |
| 295 | ans= qu->answer; |
| 296 | |
| 297 | if (ans->nrrs && qu->typei->diff_needswap) { |
| 298 | if (!adns__vbuf_ensure(&qu->vb,qu->typei->rrsz)) { |
| 299 | adns__query_fail(qu,adns_s_nomemory); |
| 300 | return; |
| 301 | } |
| 302 | adns__isort(ans->rrs.bytes, ans->nrrs, ans->rrsz, |
| 303 | qu->vb.buf, qu->typei->diff_needswap); |
| 304 | } |
| 305 | |
| 306 | parent= qu->parent; |
| 307 | if (parent) { |
| 308 | LIST_UNLINK_PART(parent->children,qu,siblings.); |
| 309 | qu->ctx.callback(parent,qu); |
| 310 | free_query_allocs(qu); |
| 311 | free(qu); |
| 312 | } else { |
| 313 | makefinal_query(qu); |
| 314 | LIST_LINK_TAIL(qu->ads->output,qu); |
| 315 | } |
| 316 | } |
| 317 | |
| 318 | void adns__query_fail(adns_query qu, adns_status stat) { |
| 319 | adns__reset_cnameonly(qu); |
| 320 | qu->answer->status= stat; |
| 321 | adns__query_done(qu); |
| 322 | } |
| 323 | |
| 324 | void adns__makefinal_str(adns_query qu, char **strp) { |
| 325 | int l; |
| 326 | char *before, *after; |
| 327 | |
| 328 | before= *strp; |
| 329 | if (!before) return; |
| 330 | l= strlen(before)+1; |
| 331 | after= adns__alloc_final(qu,l); |
| 332 | memcpy(after,before,l); |
| 333 | *strp= after; |
| 334 | } |
| 335 | |
| 336 | void adns__makefinal_block(adns_query qu, void **blpp, size_t sz) { |
| 337 | void *before, *after; |
| 338 | |
| 339 | before= *blpp; |
| 340 | if (!before) return; |
| 341 | after= adns__alloc_final(qu,sz); |
| 342 | memcpy(after,before,sz); |
| 343 | *blpp= after; |
| 344 | } |